Heretofore, the conventional method for producing polyalkylene polyamine compounds and particularly polyethylene polyamine compounds such as diethylenetriamine, triethylenetetramine, and the higher homologs was to react an alkyl halide, e.g. ethylene dichloride, with ammonia or an amine compound such as ethylene diamine and the like at elevated temperatures and pressures. These methods, while widely practiced and capable of producing commercially acceptable yields of predominantly linear polyethylene polyamines with varying amounts of heterocyclic amines, have been found to present serious disadvantages.
Separation and recovery of the polyamines is difficult and the process presents a serious problem of disposal of halide salt by-products. Moreover, the ability to select the linear and heterocyclic polyamines that are produced is somewhat limited.
Several procedures have been suggested as, for example, disclosed in U.S. Pat. No. 3,714,259 to Lichtenwalter et al, and U.S. Pat. Nos. 4,036,881 and 4,044,053 to Brennan et al, for preparing predominantly linear polyamines which do not entail the halide salt disposal problem, but ability to control the composition of the mixture of the linear and heterocyclic polyamines produced thereby is limited and/or they involve the use of relatively expensive catalysts and procedures. It would be desirable, therefore, if a process or processes could be developed which achieved greater flexibility in the selection of the linear polyethylene polyamines that could be prepared and/or involved the use of less complex and less expensive materials and process procedures.